Not applicable
Not Applicable.
This invention relates to storage systems for pressurized gasses, and, in particular, to an expandable, collapsible ambulatory storage system.
High-pressure gases are typically stored in steel or aluminum containers. For example, oxygen is stored in steel or aluminum containers (or cylinders) for use in aviation (spacecrafts, private, military and commercial airplanes), by scuba divers, in hospitals, emergency vehicles, and by patients requiring oxygen therapy. In aviation, oxygen is supplied in specially designed high-pressure canisters.
In the medical field supplemental oxygen is prescribed to patients who suffer from a variety of respiratory disorders, due to respiratory insufficiency or respiratory failures such as, obstructive pulmonary disease, chronic bronchitis, interstitial or restrictive lung disease, emphysema, congestive heart failure and during surgical operations. The typical modes of oxygen delivery are concentrators that concentrate atmospheric oxygen, pressurized canisters, high pressure cylinders made of steel or aluminum, or liquid oxygen systems that convert liquid oxygen to a gaseous state for ambulatory or domicile use. High-pressure cylinders are often wrapped with other high-tensile strength material for structural reinforcement such as carbon fiber, or other materials.
The steel or aluminum cylinders store gases at a range of pressure that depends on application. Supplemental oxygen storage devices for example store oxygen at a pressure of up to 3000 psi (pounds per square inch). For therapeutic use or other applications the pressure is lowered using a pressure regulator. In the case of therapeutic application it is regulated down to atmospheric pressure.
Existing gas storage devices suffer from many limitations, including economic, safety, ergonomic, human factors and environmental drawbacks. Aluminum or steel cylinders are expensive to manufacture and are not environmentally compatible. They are costly to distribute because of their weights and pose a safety hazard if ruptured or dropped. The economic attractiveness of these devices is diminished in a flat reimbursement healthcare system (such as under HMO""s) and in situations where it is difficult to supply patients with the required cylinders, such as patients in remote locations.
Furthermore there is a high acquisition or capitalization cost associated with purchase of infrastructure needed for entry into this business because of the per-unit cost of steel or aluminum. This poses barriers to entry and ultimately limits competition with a resulting penalty in cost of care. These issues are compounded by the high cost of manufacture.
From a safety point of view, high-pressure storage devices made of steel or aluminum can fragment when ruptured. The fragments are effectively shrapnel, and can cause severe injury or even death to people in the vicinity of the cylinder when it ruptures.
Notwithstanding the long-term rehabilitative benefits of oxygen, patient compliance as well as adoption of high-pressure containers as a supplemental oxygen source has been a problem. The existing cylinders are not portable (they are too heavy), are uncomfortable to carry, or are esthetically displeasing. In response, several lightweight high-pressure gas storage containers made from a synthetic material have been proposed.
Scholley (U.S. Pat. No. 4,932,403) describes a container in the form of a continuous length of hose incorporating a series of expanded diameter storage sections and flexible connecting sections into its length. The storage chambers are interconnected by narrow bent conduits and attached to the back of a vest that can be worn by a person. The device embodies a pressure regulator at one end, which regulates supply of compressed gas to the mouth of the user.
Scholley""s container includes an interior liner, constructed of flexible material, covered by braided fibers, which may be formed of a synthetic material such as nylon, polyethylene, polyurethane, tetrafluoroethylene, or polyester. The liner is covered with a reinforcing material, such Kevlar (an aramid fiber having a tensile strength three times the strength of steel) and impregnated by a protective coating of material such as polyurethane.
The Scholley container suffers from several limitations, making it impractical for high-pressure applications. The tubular shape of the independent containers does not provide adequate reinforcement for storage of high-pressure gas, and the narrow, bent conduits are unreliable when used in cyclical and repetitive filling and emptying applications. Furthermore it is costly and difficult to manufacture because of the required fittings, geometry of the conduits, amount of material and pieces that must be assembled. Another limitation of the Scholley container is that when the tubular high-pressure gas device is installed longitudinally within a vest, it is impractical. When the storage device is pressurized, it is as hard, rigid, and difficult to bend; and thus cannot be worn as clothing that overlaps the body.
Cowley (U.S. Pat. Nos. 3,491,752 and 3,432,060) describes a lightweight flexible pressure container made in the form of a coiled spiral tube. While compact, the device is limited to applications of short duration. Storage capacity cannot be increased by using a larger tube due to flexibility and weight penalties.
Farr (U.S. Pat. No. 1,288,857) describes a life preserver made from multiple interconnected cylinders, that are made from rubber, cloth or fabric. The geometry and configuration of the connecting pipes and cylinders pose severe challenges to manufacture and personal use, and as a result is infeasible.
Alderfer (U.S. Pat. No. 2,380,372) describes a portable container system that is built into a parachute pack to provide oxygen to parachutists. The container system includes a length of hose in the form of concentric coils that conform to the shape of the seat.
Warnke (U.S. Pat. No. 3,338,238) describes a multi-cell container which is flat or oval-shaped in cross-section. This container suffers from similar limitations as the other containers; i.e., the inability and/or expense to manufacture, and inability to conform to the body for personal use.
Sanders (U.S. Pat. No. 6,116,464) describes a container system, consisting of interconnected ellipsoidal chambers. A tubular core consisting of gas exchange apertures (for evacuation) connects the chambers. The Sanders container is also very expensive to manufacture.
Arnoth (U.S. Pat. No. 4,964,405) discloses a vest which can be worn by emergency personnel. The vest has a self-contained unit with a source of oxygen. Oxygen is stored in pressurized canisters in the front of the vest. The back of the vest includes collapsible channels through which the oxygen passes, and which contain CO2 scrubbers to remove CO2 from the gas being inhaled by the emergency personnel. These channels do not form or define pressurized containers for the oxygen.
No one, to my knowledge, has developed a light-weight pressurized container which is economical to manufacture, and is easily carried by the user.
The feasibility of using a polymeric containers for medical, emergency or recreational gas transport has never been demonstrated or reduced to practice because of design, packaging and manufacturing challenges. I have developed a new container for the transport of gases, such as medical, emergency and recreational (scuba diving, mountain climbing, hiking, etc.) gases. Of course, other gases can also be transported or carried by the container. The container or vessel includes a liner constructed of polymeric material, which, in some embodiments possesses the appearance of a wine rack, with a hollow frame that is wound in an ellipsoidal fashion by a reinforcing fiber, but molded as one integrated whole.
The hollow container serves as the storage reservoir for compressed gas, and the conduit for filling and withdrawal of the contained gaseous fluid. The container is volumetrically sized for application specific capacity, embodying filling and withdrawal mechanisms, a means of regulating the delivery pressure of the gas to the user, as well as a conserving device that delivers gas on inspiratory demand as opposed to continuously. The regulator and filling means are located anteriorly on the container.
This container will hold compressed gases at pressures of more than 2000 psi. This is achieved by the arrangement of the chambers or passages, the walls of which provide structural strength to the container when pressurized, like trusses do for a bridge. Ordinarily, materials deform when subjected to forces beyond their elastic limit. The rib-like parallel arrangement of the passages acts as a structural reinforcement for the container, expanding during filling and collapsing as it is emptied. This arrangement also provides a spring-like effect that assures geometrical integrity when the acting force is removed. The liners are further reinforced with a fiber material.
The effect of the reinforcement of the line is to amplify the tensile and compressive strength of the interconnected reservoirs or passages, by boosting the elastic limit and spring constant of the material, thereby reducing the probability of premature rupture under tension and deformation due to compressive and tensile loads.
Briefly stated, the preferred gas container or tank of the present invention defines a volume for storing gas under pressure. The volume comprises at least one generally horizontal channel, and at least one generally vertical channel which are in fluid communication with each other such that gas in the container can flow freely between the channels. Preferably, there are at least two vertical channels (one on each side of the container) and at least two horizontal channels (a top and a bottom channel). There may also be diagonal channels.
In one embodiment, the container is rigid and has a top surface, a bottom surface, a front surface, a back surface, and side surfaces, the surfaces cooperating to define the volume. A plurality of slots extend between opposite walls of the container. The slots are hollow, and are defined by slot walls, and the slot walls, in turn, define the channels. The slots can be nearly any desired shape or combination of shaped. For example, the slots can be rectangular, round, kidney shaped, oval. The slot walls can be generally flat or outwardly curved.
In another embodiment of the container, the container expands upon pressurization and contracts as gas is emptied from the container. In this embodiment, the container includes interconnected conduits which define the horizontal and vertical channels. At least one of the horizontal and vertical conduits are expandable/contractible conduits which are movable between an expanded state when the container is pressurized and a contracted state when the container is unpressurized. The expandable/contractible conduits can be accordioned, or define at least a portion of a wave.
The container or tank includes a regulator, a conserver (which preferably is remote from the container). A first hose extends from the regulator to the conserver and a second hose extends from the conserver and has a fitting on the end thereof to enable a user to breath the gas from the container. Preferably, a carrier is provided for the container to facilitate carrying of the container by the user.
The carrier can be a back pack, a purse-type pack, or a waist-pack. No matter what type, the carrier is provided with a strap operable to secure the carrier to a person. The strap includes or defines a tube for holding the hose adjacent the strap for at least a portion of the length of the strap. In one embodiment, the strap is formed as a hollow tube and defines the tube. In another embodiment the tube extends along an outer surface of the strap and the hose is threaded through the tube. In an alternative embodiment, the tube includes a slot or groove through which the hose can be pressed.
The conserver includes a body having an inhalation chamber and an exhalation chamber which are in fluid communication with each other via a first port. A diaphragm in the inhalation chamber divides the inhalation chamber into a first part and a second part. A check-valve in the first port prevents the flow of oxygen from the inhalation chamber to the exhalation chamber.
An outlet passage to which the hose connects extends from the body. The outlet passage is in communication with both the inhalation chamber and the exhalation chamber via an outlet port and an exhalation port, respectively. A check valve is placed in the outlet port to prevent gas from entering the inhalation chamber from the outlet passage. A pressure activated exhalation valve in the exhalation port to selectively opens and closes the exhalation port.
A neck extends up from the body. The neck defines a chamber and includes an inlet to which a hose is connected to place the neck chamber in communication with the container. A plunger is axially movable in the neck chamber between an upward position and lowered position. The plunger has a stem which engages the diaphragm to move the diaphragm down as the plunger moves down. A seal around the plunger defines an air-tight seal between the plunger and the neck and divides the neck into a neck upper chamber and a neck lower chamber. The plunger is biased to an upward position by a spring.
A control passage extends from the neck to the exhalation valve to place the valve in communication with the neck chamber. A supply passage places the neck chamber in communication with the inhalation chamber second section; the supply and control passages are reciprocally placed in communication with the neck upper chamber (and the container) and the neck lower chamber as the plunger reciprocates between its upward and lowered positions.